Manufacture of vehicle panels such as fenders etc. requires one or more sheet metal forming operations such as bending, drawing, trimming etc., referred to, in general herein, as stamping operations. Such operations include the use of dies wherein a first die comes in close proximity with a second die to deform sheet metal, located in between, into a desired shape. However, because sheet metal parts are thin and are subjected to relatively small strains, they are subject to the phenomenon of springback (i.e. the sheet metal deflects slightly back toward its original shape). The degree of springback in a particular panel must be determined so the dies and forming operations can be designed such that the desired final shape is met, with the effects of springback taken into account.
Springback in a part can be approximated by computer simulation of a metal forming operation, but eventually the simulation should be confirmed by deforming an actual part. Whether the confirmation test is performed in a lab or on the factory floor, typical practice includes deforming the panel within a stamping press, and then moving the deformed panel out of the press and to a dedicated fixture, where the panel is secured, and where the springback of the panel is then measured using a CMM (Coordinate Measuring Machine) or laser scanning measuring process.
When measuring springback, it is important to secure one portion of the panel in a known position so the measured deformation in another position is representative of actual springback.
Fabricating several dedicated measuring fixtures for securing and measuring a deformed part is expensive, especially when a large number of significantly different shaped panels are formed. What is desired is a way to avoid having to manufacture a dedicated fixture and move a deformed panel to the dedicated fixture in order to measure springback.